I dunno how the performance compares between those two lenses when focused closer. The 24 TSE II is excellent up close and I know it is a sharp copy because I get a touch of moire at times in some areas and I have a good feel of what the 5D3 sensor is capable of. I have used a bunch of different lenses on this body. (Currently own 11 L lenses)

My experience with the 17-40L is that the edges/borders get worse and worse as you zoom out to 17mm. I will take some images tomorrow and see how the lens is performing in that regard. ...Show more →

There are many things that could explain soft corners from the 17-40 and from other ultra wide lenses: the native optical quality of the lens, different copy variations, selection of aperture, etc.

One that is often overlooked in many samples is that because the angle of view is so wide, subject in (especially) the lower corners are often much closer to the camera than subjects in the center of the frame. Not all results can be explained by this, but I've seen a good number that can be.

Hi, today I made some shots with the 17-40L at 17mm f11 and the 14L at f11 (tested f8 but in both extreme corners were best at f11)

The 17-40L is soft at 17mm just on the very last few mm of the sensor if that. It is almost to the edge. Crop in a hair and its all good. The 14mm L II is superb, even when it has a wider angle of view and the same objects in the scene are smaller in the frame. More towards the center of the frame the 17-40L has the slight edge due mainly due to the higher magnification.

Keep in mind light was really bad compared to last time. Had to bring shadows up a tad.

Both images processed in LR (latest) with lens corrections and a touch of sharpening.

Redid the test at 25mm on the 17-40L and the 24mm TSE II bot both at f11 and it is very close. The TSE might have a VERY slight edge corner to corner but its very close.

Again, the limiting factor is the Canon sensor. The 14L II and the 24 TSE II look to be good edge to edge for a much higher res sensor. The 17-40L is too zoomed in a touch.

Once you start seeing equal or similar resolution in identical areas of scene (given equal magnification) and under close to identical conditions using different lenses you know you are just about at the limit of what the sensor can deliver.

A Zeiss OTUS is about pointless on the Canon IMHO except for the awesome performance at f1.4~f2 corner to corner.

At optimum apertures the better lenses for the Canon will just about squeeze out as much resolution from the sensor as it can deliver. Maybe with a higher resolution Canon we will see more differences between the current crop of lenses. Those who have used the EOS lenses on the A7R might have already seen them.

Thanks for shooting these additional shots. Sorry the lighting was not the same, but seems consistent between these two lenses.

First, a question: I see (apparently) that you did not use CA correction, based on the color fringing on the 17mm end, correct? Did you use the lens profiles? I'm surprised how bright and consistent the frame is from side to side on both lenses, even considering that they are shot at f/11.

Second, I see a tremendous difference in sharpness between the two lenses when viewing details like tree branches, trash on the ground, and cracks in the lane dividing cement K-rail. The softness and "smudging" go into the frame up past the lamp head and pole, well into the main part of the image again of the zoom, even at f/11 -- makes me remember how awful my 17-40 looked at f/5.6 on the sides and corners. I think this goes well beyond the sensor rez, considering the centers are probably both sharper than the 14mm edge at f/11 (unless diffraction effects are influencing). I don't think the sensor is the culprit -- I've seen nicer rez with my 5D2 and 1Ds3 for finest detail in things like fine tree branches and cracks in rocks, etc.

I don't deny the need for more sharpness in sensor, whether Canon's 21MP or Sony's 36MP -- I'd always enjoy it being affordably sharper!

Yea Dan, real shooting outdoors on a tripod at infinity focus (or close to), where I mostly use these lenses. The 14mm L II I use a Lot also for indoor architecture and sharpness is not an issue. Wish CA was lower though, It is the only negative aspect (at the apertures I use it at) of that lens.

Sneakyracer wrote:
Yea Dan, real shooting outdoors on a tripod at infinity focus (or close to), where I mostly use these lenses. The 14mm L II I use a Lot also for indoor architecture and sharpness is not an issue. Wish CA was lower though, It is the only negative aspect (at the apertures I use it at) of that lens.

In the studio with controlled light I use other lenses, not these.

Understood. I use different lenses for different subjects as well—environmental portraits of musicians, sports, landscape, night photography.

Fortunately CA is usually pretty easily and effectively counteracted in post.